1. Field of the Invention
The present invention relates in general to a method and device for molding a foamed plastic article, and more particularly to a method and device for molding a skin-covered foamed plastic article, such as a headrest cushion of an automotive seat.
2. Description of the Prior Art
In molding headrest cushions of an automotive seat, various types of molding methods and devices have been proposed and put into practical use. Some of them are of a type which uses a split mold and a shaping die. The split mold is suitable for molding an article of complicated shape because of its dividable structure. The shaping die is the member that provides the product (viz., headrest cushion) with a bore in which a structural base member is to be received.
In molding, a skin member shaped like a bag is put in the split mold in assembled condition. Then, a liquid material for foamed plastics, such as foamed polyurethane, is poured into the bag in the mold. Then, the shaping die coated with a suitable releasing agent is inserted into the mold and remains therein until the material is adequately cured and hardened. After a certain time, the shaping die is removed from the mold and the mold is divided into parts to remove the bored product from the mold. Because of the dividable structure of the split mold, the removal of the product is easily achieved.
However, due to the inherent constructions thereof, some of the conventional molding devices have encountered severe leakage of the liquid material through clearances inevitably produced in the split mold. This leakage is marked when the foaming reaction of the material becomes severe. This leak sometimes soils the product and thus lowers the quality of the finished product.